Noisy Flights

Why is the humming bird called so?

It is because of the humming sound it makes while flying.

Have you ever tried running and singing at the same time? It would be impossible wouldn’t it? You would start panting within no time! Then how does the humming bird manage this?

The secret is that the sound made by this bird during the flight is not vocal at all. It is caused by the rapid beating of its little wings, just like bees and dragon flies. This little bird beats its wings around 60 to 80 times a second!

In fact, the sounds made by the feathers of this bird are not restricted to humming alone. The elaborate courtship displays of humming birds comprise of a bomb dive from a great height. The dive is accompanied by a loud chirp. But this chirp again, is not vocal. During the dive, the bird spreads out its tail feathers, just for 60 milliseconds. The feathers vibrate for this brief period and the air passing across them gives the chirp that attracts the female’s attention.

Humming birds are the smallest vertebrates, the smallest hummingbird, the Bee Hummingbird being no more than 2.25 inches long. These creatures can hover at one place in air for a long period of time. They are capable of flying forwards, backwards, upwards and downwards, an incredible feat that no other bird is capable of! This is possible because they have wings that rotate through 180^o. Unlike most birds that flap their wings back and forth to fly, hummingbirds move their wings in the shape of an eight, so that they can move in any direction. They have strong pectoral muscles that make this possible.

Hummingbirds are mainly found in the American continents. The feed on nectar from flowers, from where they get their sugars. For proteins, they feed on insects.

Further reading:

1.http://birding.about.com/od/birdprofiles/a/whatishummingbird.htm

2.http://www.sciencedaily.com/releases/2012/09/120927091924.htm

3.http://www.sciencedaily.com/releases/2010/11/101121122532.htm

4.http://www.youtube.com/watch?v=l3XT6qoNMMQ

Forests in the sea

Whenever we talk of forests, we visualize a vast expanse of land with lots of large trees and thick lush green undergrowth…..and a variety of big and small animals and insects living in the midst of this vegetation. We may be well aware that there are different types of forests like tropical evergreen forests, coniferous forests of the temperate region, deciduous forests etc..Grasslands are also forests.

But how many of us are aware that there are forests under the sea?

Along the Pacific coasts of the North America, South America, Australia and near South Africa, the ocean beds are densely populated with the Giant Kelp. These are large algae that grow to about 90 feet high. They are brown algae and absorb light using the pigment fucoxanthin which gives them their brown colour. Large numbers of these algae grow close together forming “Kelp forests”.

Kelp grow in waters that are nutrient rich, at a temperature below 21^oC. They grow in shallow waters near the coast so that they receive sufficient sunlight.

Kelp forests are the most diverse marine ecosystems. A variety of invertebrates, fish, marine mammals and birds live in and around these forests. Large creatures like sea lions, seals, otters, or even whales may take shelter in these forests to escape from storms or predators. Kelps are known to calm down sea storms because they weaken the currents and waves. They protect the shore from wave action.

Sea Urchins feed on Kelp to such a large extent that at times they raze the entire forest to ground and prevent it from regrowing. This ecological imbalance is however taken care of if there are enough Sea Otters to prey on the urchins. Thus, the Sea Otter is a keystone species of this ecosystem and prevents it from collapsing.

In today’s times of energy crisis, scientists are trying to use Kelp as a source of renewable energy. They are trying to make fuel from Kelp using bacteria.

Further reading:

1.http://theweek.com/article/index/223581/the-mutant-bacteria-that-turns-seaweed-into-fuelnbsp

2.http://www.csupomona.edu/~biotrek/posters/kelp_anatomy.pdf

3.www.youtube.com/watch?v=ZQb9ZFWfNZE

Fish with a difference

As a habit, I go to the beach for a walk every morning. As dirty as the beach is, we rarely see any sea animals there – except crabs. But this morning, the tide was low, and I ventured far into the water, in the hope of seeing something more. And I did see something……  

A unique little creature. 

The sand was wet, with many little puddles. And in these puddles I could see some animals. They were brown in colour, about three inches long, one inch thick. In water, they would wriggle continuously. Occasionally, one would come out of the puddle, and jump about in the wet sand.

These creatures were none other than the mudskippers. They are amphibious fish. Yes, you got it right – amphibious fish. That means they can live on land as well as in water. These are one of the few species of fish that can survive when out of water.

We are aware that most land animals breathe air through lungs. That is where we get oxygen from. Fish have gills instead of lungs, and through these, they absorb the oxygen dissolved in water. When most fish come out of water, the walls of their gills stick together, so that they can no more breathe. Ultimately they die.

But what sets the mudskipper apart is its ability to breathe when out of water. Like other fish it has got gills too. But around these gills it has large chambers in which it can store water, with a bubble of air, before coming to land. So although the mudskipper is on land, its gills are surrounded by water, so that the walls don’t stick together.

The mudskipper can also breathe through its skin, as long as the skin remains moist. So it has to return to water time and again for a splash. In fact, some mudskippers remain close to water, with their tails always dipped in water. This led some early observers to believe that mudskippers breathe through their tails!

Where does the mudskipper get such a funny name from? Well – when on land, they use their front fins to move about. Both the fins are used together, like a man walking on crutches. They move about in a series of ‘skips’ - hence the name. To attract females, the males may propel themselves into air as high as two feet, with the help of these fins. Some can even stand on their tails!

Next time you visit a beach during low tide, watch out for these little wonders……  

Further reading:

1. http://www.youtube.com/watch?v=KurTiX4FDuQ

2. http://worldfishcenter.org/Naga/Naga25-3&4/pdf/NAGA_25no3n4_features_d.pdf

3. http://free-journal.umm.ac.id/files/file/09_2445_ns0805_79_89.pdf

4. http://www.mudskipper.it/Profile_file/Polgar&Crosa09_online.pdf

Jumping jacks

Had been to Konkan for a vacation last year. It was a beautiful winter morning. At a point in the ghats, we stopped at a tea stall to enjoy the view with a glass of hot chai.

As we chatted with the chaiwalla, he told us the story of the fisherman who saw dolphins in the sea a few years ago. As this news spread, these dolphins became a tourist attraction. Now, many launches are available that take tourists into the sea to see these animals of titanic fame.

We decided to go too! The sea was rough, and the boat rocked. But we continued undaunted. The boatman pointed out into the sea. And lo and behold – we could see a dolphin jump out of the water and back into it….several times. Oh! What a beautiful sight!

But have we ever wondered – what makes these ‘fish’ come out of water?

And not only dolphins, even whales show this behavior. Why?

The answer lies in the basic fact that dolphins and whales, although often mistaken to be, are not fish. So, unlike fish, they do not breathe underwater through gills. They are mammals, and like humans, have lungs for breathing. They do not take in the oxygen dissolved in water, like fish. They breathe oxygen from air.

We cannot hold our breath underwater for a long time. We have to come to the surface of water to breathe in again, unless we are carrying oxygen cylinders. Similarly, the dolphin comes to the surface of water to breathe air through a hole on its back that functions as a nostril. It takes in sufficient amount of air into the lungs and goes underwater again. It can stay underwater for about fifteen minutes. Whales breathe the same way, but some of them can remain underwater for upto an hour!

But doesn’t the water enter the lungs of these animals and choke them? No – at the base of their breathing hole, they have a flap which closes as they dive. This flap keeps the water out of the lungs. Also, as they go deeper, although the pressure of the surrounding water increases, their lungs collapse, and the water is kept out.

Further reading:

1. http://library.thinkquest.org/17963/respiratory-system.html

2. http://understanddolphins.tripod.com/dolphinblowholeandbreathing.html

3. http://www.youtube.com/watch?v=S6hNWZQeFzc

  

In the dark

The streets of Gotham were pitch dark because of the power cut. It was almost midnight. Tom could barely see a few feet ahead. As he turned the corner, he became aware of someone behind him. The footsteps came closer and closer, and before he knew it, someone nabbed him by the throat, and threw him on the floor. The masked man pointed a knife at him and began searching him for his wallet. Tom lay helpless on the ground, too scared to react.

Suddenly, something swooped down and pushed the robber over. The figure in the dark started bashing the robber. Thankful, Tom got up to his feet. He wondered who his savior was. And then, he saw the savior’s outline in the dark. It was none other than batman himself!

Of course! Who else could have spotted danger in the dark!

Yes. Bats are nocturnal .i.e. they rest during the day and hunt at night. But how do they find their prey in the dark? The do it using a special ability called echolocation. As bats fly around in search of prey in the dark, they produce sounds by clicking their tongues or contracting their voice boxes. These sounds are very high-pitched, and cannot be heard by humans. These sound waves travel through air. When they hit a flying insect, they bounce off the insect, and start travelling back towards the bat. Using its ears, the bat detects these reflected waves and knows where the insect is.

The bat knows if the insect is on its left or right depending on which ear the waves reach first. It can also make out the size of the insect depending on the loudness of the echo. A smaller insect will reflect less waves, giving a softer echo. On the basis of the pitch of the echo, the bat knows in which direction the insect is moving. An insect that is moving towards the bat will give a higher pitched echo than the original sound, whereas an insect moving away from the bat will give a lower pitched echo. The bats mind unconsciously interprets this information, the way we humans unconsciously interpret the information from our eyes or ears as sight or sound.

The bat can also use this ability to locate stationery objects, and hence to find its way in the dark.

Further reading:

1.http://www.batcon.org/index.php/all-about-bats/intro-to-bats.html

2. http://www.youtube.com/watch?v=gZxLUNHEmPw

Fine Fiddle

Every fiddler had a fine fiddle,

and a very fine fiddle had he;

Oh there's none so rare as can compare

With King Cole and his fiddlers three.

We have all heard of King Cole’s famous fiddlers three. They played fine tunes to please their master, the king. But have you ever heard of the crab that plays the fiddle?

I am talking about the ‘fiddler crab’. This species of crab is commonly found on Indian beaches. It measures about one to two inches, and can be identified by its distinctly visible ‘fiddle’.

In the males of this species, one of the claws is extremely large, much larger than the other claw, and sometimes even larger than the entire body of the crab. This claw is often brightly coloured, and is meant for attracting the female. During courtship, the males engage in a fight in which they use their large claw.

The fiddler crab feeds on algae, fungi , dead plants etc….

When this crab feeds, it picks up food from the ground and puts it into its mouth. It repeats this action several times, rapidly. It uses its small claw to feed. The larger claw remains motionless. The small claw thus moves again and again across the large claw. So the overall action looks as if the large claw is the fiddle, and the crab is playing it with the small claw!

Watching this tiny fiddler is a joy indeed!


1. http://wildphotos.net/facts/Fiddlercrab.asp?page=/facts/Fiddlercrab.asp
2. www.youtube.com/watch?v=qPAA9y7CRqo
3. http://www.dnr.sc.gov/cwcs/pdf/FiddlerCrab.pdf

What meets the eye

In mid march, I had been to Sewri for a flamingo watch. It was a thrill to see the beautiful avians take flight. But not only that,  I also got an opportunity to see a great variety of other water birds.

I felt sad that such a biologically diverse ecosystem of the Sewri mudflats is contaminated with oil spills. There are also a few wrecked boats lying near the jetty.

On one such old boat, I got an opportunity of seeing a Kingfisher take shelter. And how beautiful it was! Turquoise blue plumage, with red straps on the wings. Made me wonder where the bright blue colour comes from.

Usually, the colour of a living organism comes from a pigment. Pigments are chemicals produced by cells that not only perform some important function in the organism, but also impart a distinct colour to the organism. For example, the green pigment chlorophyll not only imparts a green colour to the plant, but its main function is to trap light energy so that the plant can make food by photosynthesis.

The fruits and flowers of plants are colourful due to pigments like anthocyanin, betalain etc..These pigments make the fruits and flowers attractive to insects, animals and birds, thus helping in pollination or seed dispersal.

The flamingoes are basically grayish white in colour. But the more they feed on shrimps, the more pink their plumage becomes. That is because, the shrimps contain the pigments alpha and beta carotenoids which are blue or green in colour. When the flamingo digests this pigment, it turns pink in colour.

 But when it comes to the kingfisher, it is an entirely new story! The colours of the Kingfisher are not due to any blue pigment, but due to the diffraction of light by the feathers. The true colour of the Kingfisher’s plumage is a dull brown! But the beautiful blue is due to the structure of their feathers, and the way their feathers reflect light.

And how can we miss out on the magnificent peacock! The peacock’s colours too are due to reflection of light – but in a different way. If you have had an opportunity to see one these beauties, you may have noticed that as you look at the peacock from different angles, you see different colours! These colours are called iridescent colours. This is seen because different waves of light interfere with each other, either enhancing each other or nullifying each other, and as a result giving rise to changing colours.

 Further reading:

1. www.biologymad.com/resources/beetroot%20pigment2.doc

2. http://www.ias.ac.in/jarch/proca/1/1-7.pdf

3. http://www.webexhibits.org/causesofcolor/7D.html

4. http://www.webexhibits.org/causesofcolor/15.html

The Traveler

Oh! I am so tired. Just returned from a long journey……900 kms……16 hours in the train…….puff- travelling can be so exhausting! We human beings find travelling tiring in spite of the hi-tech modes of transport that we use. Have we ever given a thought to how the other species ‘travel’?

Travel ? Yes, they definitely do. It is called ‘migration’. When the weather at home becomes harsh, animals and birds migrate to other regions where the weather is more comfortable. This is especially true for species living in the arctic region. The arctic winters are too cold for them. So they travel south in winter.

One such species is a bird called the Little Stint. This bird breeds in northern Europe and Russia, in July and August. In autumn, it starts migrating southwards. It spends its winters in the warmer countries of Africa, Asia, and the Indian Sub-continent. In April-May, it flies back home for the next breeding season.

Every year, the little stint flies a total distance of about 12000 kms! Hmmm……requires great deal of endurance, doesn’t it? Must be a really strong bird! But do you know why it is called the ‘Little’ Stint? Because it is only 13 cms long with outstretched wingspan of 36 cms  and weighs only 24  gms.

Then what is the secret behind its strength? Well, these birds, though small, have a lot of fat reserves in their body. If the energy supplied by food is completely utilized, their body burns these fats to obtain energy. And, they also take enough rest during their journey. They land, rest and feed in muddy areas at regular intervals of time.

Habitats of the little Stint in different seasons

Further reading: 

1. http://www.birdlife.org/datazone/speciesfactsheet.php?id=3045

2. http://orientalbirdimages.org/search.php?action=searchresult&Bird_ID=1254

3. http://www.oceanwanderers.com/LtStint.html

Introduction

Introduction

What is this life if, full of care,

We have no time to stand and stare.

No time to stand beneath the boughs

And stare as long as sheep or cows.

No time to see, when woods we pass,

Where squirrels hide their nuts in grass.

No time to see, in broad daylight,

Streams full of stars, like skies at night.

No time to turn at Beauty's glance,

And watch her feet, how they can dance.

No time to wait till her mouth can

Enrich that smile her eyes began.

A poor life this if, full of care,

We have no time to stand and stare.

"LEISURE"

By William Henry Davies.

As a child, I enjoyed being surrounded by nature. I loved visiting my native place in Konkan, where our house was in the midst of the forest. I would roam through the woods for hours together, plucking fruits and flowers, playing in the mud, and drinking the pristine water from the spring. Even back home in Mumbai, I loved the smell of the wet mud after the first shower, or simply standing by the sea shore listening to the swish-shwoosh of the waves.

But as I grew up, these likings took a back seat in the rat race called life. Realities became the priorities. Although I pursued my higher studies in Microbiology, Environmental Sciences and Education, unfortunately, I never had the time to stand and stare.

Once I got set in my professional life, I started finding time for my creative pursuits. Now I teach Biology to IGCSE and AS and A level students. AND I make it a point to follow my passion for nature. I take part in the nature trails and other activities conducted by the Bombay Natural History Society. And I feel ENRICHED.

After taking up this beautiful hobby, I discovered the vastness of nature. Nature is like god’s treasure, with magnificent jewels. Nature’s bounty is full of variety. The more you look, the more you find….each animal, bird, insect, plant or micro-organism with its own peculiarities! The world is full of marvelous forms of life….many of them that will stretch our limits of imagination! This blog is an attempt to bring to you amazing facts about living beings with whom we share our unique planet………